Lorenzo b



. t UNITED STATES PATENT OrricE'.

LORENZO TUPPER, OF NEW YORK, N. Y.

GRATE-BAR.

Specification forming part of Letters Patent No. 57,4111, dated August 21, 1866.

vented, made, and applied to use a certain newv and useful Improvement in'Grate-Bars; and I do hereby declare the following to be a full, clear, and exact description of the said invention, reference being had to the annexed drawings, making part of this specification, where Figure l is a side elevation of my improved bar, and Fig. 2 is a cross-section of the same.

The same letters indicate like parts.

Grate-bars have heretofore been made in which the rib below the bar has been corrugated, the corrugations ruiming in some instances longitudinally and in other instances vertically.

The difficulty that is generally experienced in grate-bars results from the heat causing the bars to rise in the center. or arch upward, because the expansion of the top portion under the action of heat is much greater than that of the rib below. y

The object of my invention is to equalize the expansive act-ion so that the bar may remain straight, or nearly so, under different degrees ot' temperature, and be sufficiently strong to sustain the weight of the fuel.

My invention consists in a compound corrugated rib for the lower portion of a grate-bar,

said corrugations being generallyr lengthwise 0f said bar, but at the same time 1n a waving or Corrugated form, thus forming a compound By this mode of construction the re-surface of the grate-bar is stitfened, s0 that it will not warpy sidewise or laterally, and the Waving lines of the 'corrugations allow the bar to extend lengthwise under the action of heat, said corrugations in the two directions giving to the east-metal rib a slight amount of elasticity sufficient to allow of expansion and contraction without injury to the parts.

In the drawings, a represents the upper or re surface of the bar; b b, the ends that rest upon bearers, as usual; o c, the lugs t0 keep the grate-bars the desired distance apart. d

The grate-bar formed with a straight, vor I nearly straight, surface for the fuel, and With a supporting-rib 'having compound corrugations, as an'd for the purposes set forth. l

In witness whereof I have hereunto set my signature this 29th day of March, A. D. 1866.

L. B. TUPPER.

Witnesses Cans. H. SMITH, GEO. D. WALKER. 

